Stock Blasty carb. line routing

Braaaptor

Member
Dec 1, 2009
2,169
114
48
Hamlet, NC
I'll just leave this here... Might help clear up questions about which carburetor hose goes where on a stock Mikuni carby... The vent lines and the bowl drain spillaway line are in Helix Red. The fuel supply line to the carburetor is in Yamaha Grey. Clamps are optional. I'm a stickler for details, so guess what? I used 'em!

007-5.jpg


The two short vent lines simply slip into their guides on either side of the carb. (LH one shown here) and open to the atmosphere.

006-4.jpg


RH vent line also just opens to the atmosphere.

005-4.jpg


The long spillaway tube for the bowl drain routes like this. After it passes through the lower engine mount, it is open to the atmosphere. This is to allow the contents of the carb's fuel bowl to drain safely when the drain screw is opened. You can secure this line to the motor mount with a zip tie if needed. (I left the chain, shift lever, and flywheel cover off of the Blasty to get a better pic here.)

Hope this helps somebody. Vent lines by Helix Racing. Clamps by Moose Racing. Blaster by Yamaha. Assembly by NickTodd's Quads. :D
 
Last edited:
what kinda carb cap is that???? swweeeeeeet
 
what kinda carb cap is that???? swweeeeeeet

Moose Racing. They look badass and come in other colors, too! I posted a DIY on how I installed it a few weeks ago. Search "Aftermarket carburetor cap install" on this forum, and you'll see it. :D
 
This helped me out alot. But im still running into problems.. When i turn the gas on, it starts to pour out the vent line and the bowl drain spillaway. could anybody help me with that?
 
This helped me out alot. But im still running into problems.. When i turn the gas on, it starts to pour out the vent line and the bowl drain spillaway. could anybody help me with that?

Yup, I'll try. Even though this isn't really a thread for asking questions.... Your inlet needle is not sealing properly in the carburetor. It likely has a piece of trash stuck between the needle and the seat, so that even when the float comes up and tries to push the needle into the seat, the needle won't seal and fuel keeps flowing into the carbuertor until it overfills and fuel starts coming out of the overflow/vent tubes.

My advice is to tear the carburetor apart, clean it up throughly, and reassemble everything. If you still leak, its time for a $ 15.00 carburetor rebuild kit which comes with a new needle and seat. Unless your float is damaged (full of fuel from a hole so that it won't float), this will solve the problem.
 
what is the black line that goes into the engine for on right side right underneath cylinder

thats the transmission vent, it crosses over behind the carb and follows the top frame rail, up past the fuel petcock below the tank, and up to under the hood, it is also just open to free air
 
i want that carb cap!! also where did you get the colorful tubes lol?

Helix Racing makes a variety of colored fuel lines and vent hoses. I bought a package of solid red fuel line from them and cut the tubing to fit. I believe you need 1/8" ID tubing for the carb. vents and 3/16" ID tubing for fuel line. At least on a stock Blaster carb. Aftermarket carbs over about 30mm often have a bigger fitting and therefore take 1/4" ID fuel line.
 
This helped me out alot. But im still running into problems.. When i turn the gas on, it starts to pour out the vent line and the bowl drain spillaway. could anybody help me with that?

check float height and clean where the needle valve seats and the float could be cracked
 
Thanks im a newby as well and this helped a lot! Been puzzled by it!
but I have another pipe that im puzzled about. Soneone told me to plug it onto the carb but something doesnt look right to me.....
where does that go? Its on the right hand side just under the carb??? I added a pic.
 

Attachments

  • 20150719_105429.jpg
    20150719_105429.jpg
    1.4 MB · Views: 1,232
That port on the carb doesn't do anything. It's not drilled out on a Blaster. The transmission vent needs to be routed as awk mentioned above. Make sure the hose goes up to the steering stem hoop and then back down a little ways and then is left open.
 
That port on the carb doesn't do anything. It's not drilled out on a Blaster. The transmission vent needs to be routed as awk mentioned above. Make sure the hose goes up to the steering stem hoop and then back down a little ways and then is left open.

Awesome thanks! the previous owner had it short so I assumed it must be plugged in somewhere...